Nautical parallel ruler



0. WILSON.

NAUTICAL PARALLEL RULER.

(No Model.)

No. 375,590. Patented Dec. 27, 1887.,

Wi'tm 0M2 0 N, PETERS, Phnlo-Lilhognpher. Wnhingion. n. c.

* UNITED STATES PATENT OFFICE.

CHARLES WILSON, OF ROOKPORT, MAINE.

NAUTICAL PARALLEL RULER.

SPECIFICATION forming part of Letters Patent No. 375,590, dated December 27,1887.

Application filed May 3, 1887. Serial No. 236,996. (No model.)

To (LZZ whom it may concern.-

Be it known that I, CHARLES WILsoN, a citizen of the United States, residing at Rockport,in the county of Knox and State of Maine, have invented new and useful Improvements in Nautical Parallel Rulers, of which the following is a specification.

My invention relates to improvements in nautical instruments; and it consists inthe peculiar construction and arrangement of the various parts for service, substantially as hereinafter fully described, and particularly pointed out in the claims.

The primary object of my invention is to provide an improved implement of the class named especially adapted for shaping and laying out courses on charts which shall vbe accurate and easy of operation, readily adjusted to lay out different courses, and simple,-compact, and cheap in construction.

In the accompanying drawings, Figure 1 is a plan view ofa combined implement embodying my invention in position on a chart to shape and lay off the course of the vessel there on, and Fig. 2 is 'a perspective showing the parts thereof separated.

Referring to the drawings, in which like letters of reference denote corresponding parts in all the figures, A A designate the parallel rulers, which are connected by the swinging links a in the usual manner, and are provided with the lugs a for conveniencein using. One

of therulers A has a divider-leg, B, pivotally secured to one end, as shown, and the other ruler, A, is provided at the center of its outer side edge with a fiat rounded point, 0. This point 0 is the center of a protractor, D, which projects from the edge of the ruler A and is formed integrally with the same.

In Fig. 2 I have shown an indexarm, E, as pivoted to the point C and extending out over the protractor D. This index-arm has its ends provided with upwardly-projecting spurs or points 6, which form sightpoints. This arm is used when it is desired to change the course of the vessel during the voyage by taking the bearings of objects on the shore, as hereinafter described 5 but in laying off the course of a vessel from one port to another on the chart this arm E is not used, but a cord, F, (shown in Fi 1,) used instead.

In laying out the course of a vessel on the. chart from one port to another the center G of the protractor is placed over the starting port on the chart, which is the position of the 5 by the number of points or degrees marked on the protractor at the point where the cord crosses it.

When the vessel is on an inland voyage or coasting along the seaboard,the bearings of objects on shore or which may be sighted in the water can be readily ascertained. These bearings are found by placing the device on the deck or compass-house just above the steeringcompass with the parallel rulers at right angles to the line of the vessel. now swung around until the object can be sighted thereover. The angle of the object to the course of the vessel will be thus ascertained and the true bearing of the object may be readily learned.

By securing the device in a convenient place on one of the transverse walls of the cabin in such a position that the ruler A will be parallel with the floor of the cabin and the protractor be depending from the same, the list of the vessel may be readily determined, as the arm E will swing in front of the protractor and will be always in a vertical position, as will be readily understood.

The armE is 7 The divider-leg,in connectionwith the ruler o vice,it can be manufactured at a trifling cost, andits advantages need not be elaborated here.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. A nautical instrument comprising apair of parallel rulers, a divider-leg pivoted to one of said rulers, and a protractor formed integrally with the other ruler and projecting from the side edge of the same, substantially as set forth.

2. A nautical instrument comprising a pair of parallel rulers, a divider-leg pivoted to one of the rulers, a protractor formed integrally With the other ruler and projecting from the side edge thereof, and an index seeured to the rulers and extending out over the protractor, substantially as described.

CHARLES 'WILSON.

Witnesses:

N. 'I. TALBOT, O. F. RICHARDS. 

